2007 WD5

2007 WD5 is a near-Earth asteroid that was discovered on 20 November 2007 by the Catalina Sky Survey. Its elliptical orbit extends to beyond the orbit of Mars in the main asteroid belt. His sun next path point is, however, just inside the Earth's orbit. Although the perihelion is slightly more than one astronomical unit, but the elliptical orbit of the earth he crosses yet. He belongs to the group of the Apollo asteroids. With a diameter of about 50 meters, it is a relatively small object. Nevertheless, he was being watched more closely, because its orbit passes near the Earth. Further observations gave scientists enough data to determine that the asteroid poses no threat to the Earth.

Possible collision with Mars

In the orbit determination but was determined that he might meet Mars. On 30 January 2008, at about 12 UTC clock, there was a close encounter. According to the latest data path he has the red planet but most likely not taken. He flew past at a distance of 26,000 kilometers at the center of the planet. This means a distance of approximately seven Mars radii to the surface. However, according to recent calculations, there was still a chance of 0.01% that 2007 WD5 hitting Mars, as there were uncertainties about the precise orbit of the asteroid. Meanwhile, higher collision probabilities were calculated up to 4% (or 1 to 25).

Such a collision would have created a crater diameter of about 800 meters. In 1908 in Tunguska in Siberia should have collided with the earth like a large asteroid. But It was not a crater, but since the object disintegrated in the dense atmosphere before it hit the ground. The Martian atmosphere is much thinner than that of Earth, why would there reach the ground.

Scientists hoped to observe this event and its consequences with various Mars probes. Mars Express ESA and Mars Reconnaissance Orbiter in orbit, as well as the rovers Spirit and Opportunity on the surface of Mars (all three NASA) would have had the best opportunities.